Møller and Warren: HST images of a galaxy group at z=2.81, and the ....

Figure 1. HST Wide Field Camera 2 sub-pixelised image of a region 43 arcsec by 17 arcsec around the quasar PKS0528-250 (marked Q), showing the three galaxies S1, S2, S3. The size of each sub-pixel is 0.05 arcsec. The upper panel is a weighted average of the data for the three filters, from all 30 orbits. The lower panel is the same image convolved with a Gaussian profile of sigma=1.3 sub-pixel. An inset panel shows a small region to the S of the quasar after subtraction of the quasar image, revealing the image of S1. The scale is shown by a horizontal bar of length 3 arcsec.